Discovered major billing error with SDG&E in San Diego. Client has 2.2MW solar system on time-of-use rate AL-TOU. Solar production during peak hours (4-9 PM) should get highest credit rate ($0.52/kWh). But SDG&E is applying ALL solar credits at off-peak rate ($0.28/kWh). Been going on for 8 months. Their explanation is that solar production gets "netted" at end of billing period, not real-time. This costs client about $18,000/month in lost credits.
SDG&E solar time-of-use billing error - credits applied to wrong period
Carol - that's definitely wrong. California net metering 2.0 requires time-of-use crediting. Solar production at 5 PM should get peak rate credit, not off-peak. SDG&E's billing system might be broken.
Bob's absolutely right. I've audited dozens of California solar accounts. TOU crediting is fundamental to NEM 2.0. File a complaint with CPUC immediately. This could affect hundreds of SDG&E solar customers.
Filed CPUC complaint yesterday. Also contacted three other SDG&E solar customers - they're all experiencing the same issue. Looks like a systematic billing system problem, not isolated error.
Carol - I think I know what happened. SDG&E upgraded their billing system in January and it might not be handling interval data correctly for solar accounts. Same thing happened with PG&E a few years ago.
Hannah might be onto something. SDG&E did mention "system upgrades" when I pressed them on the issue. But they claim the billing is correct per tariff language. Clearly it's not.
Had similar TOU crediting issues with APS after their billing system upgrade. Took 6 months and CPUC intervention to fix it. Document everything and keep escalating. Don't let them claim it's "working as designed."
Time-of-use net metering billing errors are unfortunately common after utility system upgrades. California's NEM 2.0 requires accurate interval-based crediting, not simple monthly netting. Document the tariff requirements, calculate the financial impact, and escalate through both utility channels and CPUC complaint process. These systematic errors often affect many customers and can result in significant refunds once corrected.